Download Pool Tip #39: Solar Panels (PDF format, 0KB)

There are primarily two types of active solar heating systems used to heat pool water – glazed and unglazed.

Glazed systems use black chrome–plated copper absorber plates with a low iron tempered glass covering. They can operate year ’round in harsh climates, but require transfer fluid and heat exchangers. A booster pump to lift water to panels installed on a roof may also be needed.

Unglazed systems are inexpensive for use in warm climates and outdoor seasonal pools. Black thermoplastic rubber or polypropylene absorber plates are utilized. Water circulates directly through collectors, using the pool pump, and two heat sensors connected to a solar controller. One sensor measures pool temperature, and the other measures temperature at the controller surface. If temperature differential is significant, the controller sends a signal to a motorized valve that closes and directs water through the collectors.

Pools that use solar panels as the sole means of heating pool water, or as an aid in reducing the cost of operating traditional fossil fuel heaters, can mount panels on a roof of the house, garage or adjacent structure; on a deck rack, or on the ground. Panels should not be placed where nearby trees or buildings will create shadows and the panels will wind up being in the shade part of the day. Ideally, panels should be installed so they face due south. But if installed within 15 degrees east or west of due south, the loss of performance will be insignificant.

For year round operations, angle the panels toward latitude. For instance in Southern California, panels should be set at an angle of 32 to 34 degrees north latitude. Pools in New England should set their solar panels to between 41 and 47 degree north, depending on their exact location. To take advantage of seasonal variations, pools operated only during the Summer months should angle panels at latitude minus 10 to 15 degrees. For Winter heating, place panels on a latitude plus 10 to 15 degree angle.